BMW F30 Remote start project, made with Arduino

This project allows to do this things:

• If the engine is off, remote start the car with a triple click on the lock button of the OEM keyfob.
• After 15 minutes from remote start, if no one started driving, automatically shut off the car
• If the engine is on, remote stop the car with a triple click on the lock button of the OEM keyfob.
• You have to unlock the car before driving it (why wouldn't you) or it will perform an emergency anti-thief stop

The Arduino, thanks to the MCP2515 board, constantly listen to the BMW K-CAN2 bus, looking for a triple lock button click. If found, it starts a 18 seconds long operation, during which it does those steps:

1. Turns on the in-car keyfob
2. Unlocks the car
3. Locks the car
4. Virtually presses the start button, turning on the ignition
5. Waits some seconds, to let the engine be ready to start.
6. Virtually presses the brake and the start button, turning on the engine
7. Turns off the in-car key.

What happens if a thief enter the car (by smashing the window) and tries to steal it?

If someone tries to engage a gear with the car remote started, without unlocking it with a keyfob first, the car automatically shuts off.

The spare key is always in the car. Wouldn't this be enough to allow a thief to turn on the engine?

Yes, but actually no. The Arduino turns on the keyfob only when it needs it to remote start. Normally the key isn't powered so the car doesn't see it and can't be turned on!

Why do the Arduino open and close the car before starting the engine?

The lock and unlock thing is needed to be able to turn on the ignition. This is because of the BMW security protocol, which disables the possibility of turning on the car if the car wasn't opened before. This is not a security issues though, because this process happens in 2 seconds and the car remains open for just 1 second.

Here's a list of things you need for this project:

• Arduino Nano
• LM2596S voltage regulator board, with the output regulated to 5V
• MCP2515 Canbus board (Niren)
• 6x Relay Board with 5V relays
• 2x 560Ω (to replicate the start button internal 560Ω resistor)
• 1x 1100Ω (to replicate the 12mA current outputted by the hall sensor inside the brake light switch)
• The spare keyfob

You can get those resistance values by putting more resistors in series and sum the resistance value. For example:

• to get a 550Ω resistance, you can put 220Ω and 330Ω resistors in series!
• to get a 1100Ω resistance, you can put 1kΩ and 100Ω resistors in series!

You have to do the wiring for:

• KCan2 bus
• 12V and GND
• Brake light switch
• Start button switches
• Keyfob battery
• Keyfob lock switch
• Keyfob unlock switch

KCAN2

Attention: the OBD2 port doesn't have KCAN2. You can't use it. You have to take KCAN2 from the FEM

• KCAN2_H: FEM A173*8B, pin 50
• KCAN2_L: FEM A173*8B, pin 49

12V and GND

Attention: you can't use the 12V plug as power source, you need an always-powered 12V source. You can find it at the FEM.

• 12V: FEM A173*3B, pin 33
• GND: FEM A173*3B, pin 6

Brake Light Switch and Start-Stop Button

Here you can see how to wire break light switch and start/stop button:

• The start-stop button wiring is right behind the switch button, just pull it out.
• The break light switch wiring is above the brake pedal.

KeyFob Power

You have to interrupt the battery positive connection, split it in 2 wires and feed them inside the relay:

KeyFob Lock and Unlock buttons

You have to simulate the press of the switch using the relay. To do that, just hook to the key switches like that:

Schematic

You can follow this schematic to build everything. Note: this schematic shows a 8x relay board, but you can use a 6x one

Final look

This is the final look, with the spare key wired. You have to hide it somewhere inside the car. (it's ugly, I know. You can make it definitely better)

autowp for arduino-mcp2515 library

If you like my work, feel free to donate me! I would highly appreciate it!